1. Field
The described technology relates generally to an organic light emitting diode (OLED) display and a manufacturing method thereof. More particularly, the described technology relates generally to an OLED display including a pixel circuit including a plurality of thin film transistors and one or more capacitors, and a manufacturing method thereof.
2. Description of the Related Technology
Unlike a liquid crystal display (LCD), the OLED display has a self-light emitting characteristic so that a separate light source is not required. Therefore, the dimensions and weight thereof may be reduced. Further, because the OLED display has high quality characteristics such as low power consumption, high luminance, and high reaction speed, the OLED display is appropriate for use in a mobile electronic device.
In general, the OLED display includes gate wires provided on a substrate and extended in one direction, data wires extended in a direction crossing the gate wires, a pixel circuit connected with the gate wires and the data wires and including a switching thin film transistor, a driving thin film transistor, a driving thin film transistor, and one or more capacitors, and an organic light emitting diode connected with the pixel circuit.
Recently, a thicker insulation layer is formed between an active layer and a gate electrode of the driving thin film transistor compared to the switching thin film transistor in order to increase the driving range of a gate voltage applied to the gate electrode of the driving thin film transistor.
However, when an impurity is doped to a source area and a drain area of the active layer of each of the driving thin film transistor and the switching thin film transistor using the gate electrode as a mask, the impurity may not be easily doped to the active layer of the driving thin film transistor because the thicker insulation layer compared to the switching thin film transistor is formed between the active layer and the gate electrode of the driving thin film transistor.
Accordingly, the thickness of the insulation layer formed between the active layer and the gate electrode of the driving thin film transistor cannot exceed a predetermined thickness for impurity doping with respect to the active layer of the driving thin film transistor.